The invention relates to a device for conveying substrates through a substrate processing plant.
Devices of this kind are known for moving substrates, especially CDs, through cooling and drying devices. The substrates are placed into baskets moving on a circular path or into slots provided in circular devices. Such carousel transporting devices, however, have great dimensions and require large size drive devices so that such known devices are cost-intensive. Furthermore, loading of such carousel transporting devices with substrates, respectively, removal of substrates therefrom, is difficult and requires high constructive expenditures.
For devices of the aforementioned kind it is also known to employ a screw conveyor which rotates and moves forward the substrates positioned in the conveying path. This has, however, the disadvantage that a relative movement between the screw conveyor and the substrates occurs, generating friction which causes particles to be rubbed off and thus results in contamination.
From DE 43 41 634 A1, upon which the present invention is based, a device for transporting disk-shaped substrates in a substrate treatment device is known in which three toothed belts are provided with which the substrates can be conveyed through the treatment device. This device, however, is designed for only a single substrate shape and size and cannot be adapted to different specifications, such as, for example, different substrate sizes.
From U.S. Pat No. 4,947,784 a device for transferring wafers from a first wafer securing device (wafer cassette) into a second wafer securing device (wafer boat) is known. Such a so-called handling device for wafers is not designed for transporting wafers through a treatment device and is not suitable for this purpose.
From DE 195 30 858 C1 a handling device is known in which the wafers are transported by suction plates. The handling device of DE 195 29 945 A1 realizes gripping and securing of flat substrate by an inner gripping device, wherein the gripping device engages a hole provided at the interior of the substrates, with the gripping device supported at the edge of the inner hole.
It is an object of the invention to improve a device known from DE 43 41 634 A1 such that an adaptation of the device to different specifications, for example, different substrate sizes, is possible in a simple manner.